Excavation and Trenching Safety Flashcards

When must a competent person inspect an excavation?

Answer: Daily and after any hazard-increasing event such as rain

OSHA requires a competent person to inspect excavations daily and after any event that could increase hazards, such as rainfall or vibration.

What is the maximum depth of an excavation before a ladder or other safe means of egress is required?

Answer: 4 feet

OSHA mandates that a ladder, stairway, or ramp be provided in excavations deeper than 4 feet.

Which soil type is classified as the most stable under OSHA's soil classification system?

Answer: Type A

Type A soil is the most stable, exhibiting high cohesiveness and requiring the least-aggressive protective system.

A trench is 6 feet deep and 3 feet wide. Workers must not be in the trench unless:

Answer: Adequate cave-in protection is in place

OSHA requires that cave-in protection (sloping, shoring, or trench box) be installed before workers enter any trench 5 feet or deeper.

What minimum distance must spoil piles be kept from the edge of an excavation?

Answer: 2 feet

OSHA requires excavated material (spoil) to be kept at least 2 feet from the edge to prevent it from falling back into the excavation.

Which condition would cause a competent person to classify soil as Type C instead of Type B?

Answer: Water is seeping into the excavation

Water seeping into an excavation indicates unstable conditions consistent with Type C, the least stable soil classification.

Before beginning excavation work, what underground utility notification requirement must be met in most US states?

Answer: Contact 811 (Call Before You Dig) at least 2–3 business days in advance

Federal and state laws require contractors to notify the 811 one-call system before digging so utilities can be located and marked.